Modelización en Geografía Física.-Landscape Evolution Modelling - LAPSUS

Abstract

ABSTRACT Landscape evolution modeling can make the consequences of landscape evolution hypotheses explicit and theoretically allows for their falsification and improvement. Ideally, landscape evolution models (LEMs) combine the results of all relevant landscape forming processes into an ever-adapting digital landscape (e.g. DEM). These processes may act on different spatial and temporal scales. LAPSUS is such a LEM. Processes that have in different studies been included in LAPSUS are water erosion and deposition, landslide activity, creep, solifluction, weathering, tectonics and tillage. Process descriptions are as simple and generic as possible, ensuring wide applicability. Vegetation-effects can be included. Interactions between processes are turn-based: volumes of one process are calculated and used to update the DEM before another process starts. LAPSUS uses multiple flow techniques to model flows of water and sediment over the landscape. Though computationally costly, this gives a more natural result than steepest descent methods. In addition, the combination of different processes may create sinks during modelling. Since these sinks are not spurious, the model has been adapted to deal with them in natural ways. This is crucial for several purposes, for instance when studying damming of valleys by landslides, and subsequent infilling of the resulting lake with sediments from upstream.